The present application relates to a method and apparatus for automatically applying a sheet material over a bulky object, and more specifically, to a portable apparatus adapted to be mounted onto a forklift, which may be used to position and automatically apply a tarp over a load, for example, on a flatbed trailer.
Trucks, trailers and railway cars with flatbeds are widely used to haul a variety of loads. Typically, a sheet material, such as a tarp, is applied over a load on a flatbed to protect the load from external elements during transportation. At the present time, this is typically accomplished by manually placing a tarp over the load, for example by somehow throwing a tarp over the load to suspend and connect the sides of the tarp to the corresponding sides of the flatbed. To this end, oftentimes, at least one worker must climb up on top of the flatbed or the load itself to effect the proper arrangement of the tarp. This is a rather dangerous operation because the worker(s) face the risk of falling from the load or the flatbed and injuring themselves. Furthermore, manual application of a tarp is labor intensive because it typically requires a number of workers to work together, and is still fairly time consuming.
Some regulatory authorities have attempted to implement a regulation to protect workers from tarp application-related injuries. For example, it is understood that Canada has already implemented a regulation prohibiting a worker from climbing up on top of a load without fall protection when applying a tarp. Various states in the United States may soon pass similar regulations. To comply with such regulations, however, would require adequate means for automatically applying a tarp without manual labor. To this end, various types of tarping stations have been proposed in the past. For example, one type of a tarping station includes a frame, within which a trailer with a load drives in. Then, a tarp is applied over the load similarly to how an automatic garage door is closed. Tarping stations suffer from several disadvantages. First, a tarping station requires that a load be transported to the station each time a tarp is to be applied. This is often not convenient and time-consuming especially when multiple loads are scattered around the field. It would be preferable to be able to automatically apply a tarp over a load where the load is situated. Second, a tarping station takes up a fairly large space, and also its surrounding area must be cleared at all times to permit loads coming in and out of the tarping station. These are tough conditions to meet when space is limited. Third, a tarping station is typically very expensive.
A need exists for a method or apparatus that allows for easy application of a tarp over a bulky object, such as a load on a flatbed trailer, which is safe, quick, and does not require a substantial amount of labor. Preferably, such apparatus is easily maneuverable to be transported to the load, is compact in construction, and relatively inexpensive as compared to a conventional tarping station.
The present invention provides a method and apparatus that would meet all the needs described above. Specifically, the invention offers an apparatus for applying a sheet material over an object, such as a load on a flatbed trailer. The apparatus is adapted to be mounted onto a forklift. The apparatus includes a framework having a tray portion, and a plurality of first rollers rotatably coupled to the tray portion. The apparatus further includes a drive system for automatically rotating the plurality of first rollers in both clockwise and counterclockwise directions to load the sheet material onto and out of the tray portion. In one embodiment, the drive system is a hydraulics system configured to hydraulically drive the plurality of first rollers. Optionally, the apparatus further includes second rollers rotatably coupled to the tray portion. The plurality of second rollers are located adjacent to and in parallel with the plurality of first rollers so that the rotation of the first rollers causes the rotation of the second rollers to cooperatively feed a sheet material onto and out of the tray portion.
In operation, the apparatus constructed according to the present invention is mounted onto a forklift. To apply a sheet material over an object, first, the sheet material is placed on the tray and one side of the sheet material is engaged between the plurality of first rollers and the tray (or between the plurality of first rollers and the second rollers). One way of accomplishing this is to place the sheet material adjacent to the tray, to engage one side of the sheet material between the plurality of first rollers and the tray, and to automatically rotate the plurality of first rollers in a predetermined direction so as to draw in the sheet material onto the tray. Second, with the sheet material thus placed on the tray, the forklift is maneuvered to place the tray adjacent to the object over which the sheet material is to be applied. Third, the plurality of first rollers are rotated in a direction to roll out the sheet material from the tray, i.e., in the direction opposite from the direction for drawing in the sheet material onto the tray.
To remove a sheet material from an object, a generally opposite procedure is performed. Specifically, after the apparatus of the present invention is mounted onto a forklift, the forklift is maneuvered to place the tray adjacent to the object. Then, one side of the sheet material is engaged between the plurality of first rollers and the tray. Thereafter, the plurality of first rollers are rotated automatically in a predetermined direction to roll in the sheet material onto the tray.
According to one aspect of the present invention, the apparatus described above may further include at least one retractor slidably coupled to the framework of the apparatus. The retractor includes a sheet material engagement portion that is configured to be engaged with a sheet material. The retractor is drivably coupled to the plurality of first rollers (or the second rollers, if provided) so that the rotation of the first rollers causes linear movement of the retractor in a direction perpendicular to a line of the plurality of first rollers. In one embodiment, the sheet material engagement portion of the retractor is formed of a plate and a pin extending generally perpendicularly from the plane of the plate. The pin is configured to receive one of the holes or D-rings typically arranged along sides of a sheet material (tarp). Thus, when the holes or D-rings of a tarp are hooked onto the pins of the retractors, and the first rollers are rotated, the retractors will be xe2x80x9cretractedxe2x80x9d while carrying the tarp, to thereby introduce the tarp into between the plurality of first rollers and the tray. Therefore, the retractors serve to facilitate initial engagement of a sheet material with the plurality of first rollers and the tray.
According to another aspect of the present invention, the plurality of first rollers are replaced with a singular first roller, and the plurality of second rollers are replaced with a singular second roller.
As will be apparent from the foregoing summary, the present invention provides an apparatus and method that permit safe and easy application, and removal of, a tarp with respect to a bulky object, such as a load on a flatbed trailer. The apparatus is portable, and thus may be readily mounted onto and transported by the standard forklift truck, to thereby facilitate the transportation, elevation, and placement of a tarp carried by the apparatus. Further, once the apparatus is properly positioned relative to the load, the application and removal of a tarp with respect to the load is substantially automatic. Therefore, the present invention offers a safe, quick, and non-labor-intensive method of applying a tarp over a bulky object.